Method of manufacturing insulating sleeves



July 9, 1935.

o. E. VILEN ET AL METHOD OF MANUFACTURING INSULATING"SLEEVES PatentedJuly 9, 1935 METHOD @MANUFACTURING INSULATING sLEEvEs Olof Einar Vilnand Torsten, Gunnar Bergnhr,

Stockholm, Sweden, assignors, by mesne assignments, to AktiebolagetArki, Sweden, acompany of Sweden Application July 21, 1932, Serial No;623,694 In Sweden March 13, 1931 1 Claim.` (Cl. 154-28) The presentinvention`relates to a method of manufacturing insulating sleeves of aninsulating sheet or quilt of the kind which consists of a layer or bodyof sea-grass, particularly dried eel 5 grass, or the like, interposedbetween external layers or sheets of paper or the like, and theinvention has for its `purpose to produce an inexpensive and eicient,pipe covering or insulation which shall have the same excellentinsulating l property as the said material.

The method according to the invention is principally characterized bythat the external layer of a strip of such insulating quilt ismoistened, at least on one side of the strip, after which the l strip isrolled or coiled, for instance on a rod or axle, to an approximatelycylindrical shape and is retained in such coiled shape, for instancerbymeans of a surrounding metal sleeve or Athe like,

while said coil is dried by the application of heat,

after which the coiled strip is removed from the metal sleeve. Themoistening of the external layer of the strip of quilt may suitably beeffected by applying to the same a sheet, orA several sheets,

of paper, fabric, or the like, coated with a suitable paste or glue, ormoistened in other manner,

and said sheet `Vof paper may also suitably be folded over the oppositeedges of the strip.

Thus, when carrying out the method according to the invention, a stripof a suitable width is cut from an insulating quilt of theabove-mentioned kind, yafter which the external paper layer of the stripis to be moistened, at least o'n one side thereof, which may be effectedby direct application of water. l

Afterwards this strip` is to be rolled or coiled to an approximatelycylindrical shape. However, since such a strip cut from a piece of quiltis generally open at both edges, so that the body of insulatingmaterial, `the eel grass, interposed be- 40 tween the two external paperlayers, might easily be pressed out at the edges of the strip, whencoiling the same, it is advantageous rst to seal said edges, which maysuitably be effected by placing the cut strip of quilt on a sheet, orseveral sheets, of paper, fabric, or the like, after a suitable paste orglue, whereby, when the strip of quilt is placed on the same, the'external layer of the strip becomes simultaneously moistened,

cr the sheet of `paper may be moistened in some l otherfmanner and, whenapplied to the strip of quilt and folded around the edges of the same,the sheet of paper may be fastened to the strip by means of staples orin other suitable manner, or said sheet of paper may be moistened afterit has been fastened to the strip of quilt.

When the external layer of the strip of quilt has been moistened in onemanner or other, as above stated, the strip of quilt is rolled or coiledby hand orrby mea-nsA of a suitable machine, for instance around a rodor around an axle or mandrel, so that said strip obtains anapproximately cylindrical shape, and when so coiled it is inserted in acylinder or sleeve of metal or the like.

The accompanying drawing shows a cross section of the strip of quiltcoiled around the rod or axle and inserted in the metal cylinder.denotes the strip of quilt having external paper layers 2, 2, and 3 isthe surrounding sheet of paper folded over the'edges of the strip. Thestrip is coiled around the rod or axle B so that the edges of the stripoverlap, and the strip is placed in the metal cylinder l. .coiledinsulating strip therein is then placed in a drying chamber to be dried.During thedrying the moisture evaporates from the external layer of thestrip and from the surrounding sheet of paper, and the coiled strip ofquilt will therefore retain the cylindrical shape which it has obtainedduringl the coiling. When the drying is completed, the cylinder is takenout of the drying chamber and the coiled insulating sleeve is removedfrom the same.

By the treatment above described the result is attained, as alreadystated, that the coiled `strip of quilt retains the shape illustrated inthe drawing. The' insulating sleeve thus produc-ed is elastic orresilient, however, so that after its overlapping edges have beenseparated and the sleeve has been passed over and placed around a pipeor the like, the sleeve will resume its closed shape so that the edgeswill again overlap;

If a bent tube is to be insulated, a suitable number of more or lessV-shaped cuts are made in the insulating sleeve in that Yside of thesame vwhich will have the smallest 4radius of curvature n placed aroundthe pipe. y

Said cylinder with the when the sleeve has bee 10 least on one side of astrip of such insulating quilt by applying to the same a sheet of paper,fabric or the like coated with an adhesive, folding said sheet of paperor the like over the edges 0f said strip, ceiling said strip to anapproximately cylindrical shape, and drying said coiled strip by theapplication of heat while retaining its coiled shape.

oLoF EINAR VILN. TORSTEN GUNNAR BERGNHR.

